Forklifts are commonly used for loading and unloading pallets which are stacked with various goods from tractor trailers and other carrier vehicles. Often a carrier vehicle arrives at a site where no forklift vehicles are available. The accompanying manual labor necessary for unloading as would be required under those circumstances is often unavailable and always expensive. Similarly, it may be uneconomic to keep a forklift at all the places where it might be used. Thus, various apparatus have been suggested for transporting a forklift with the carrier.
One obvious solution to this problem is to load the forklift on the bed of the carrier. That is not a practical solution because it takes up space which may otherwise be filled with cargo.
A solution suggested by several patents is to provide a pair of pockets on the trailing end of the carrier vehicle into which the forks of the forklift are inserted. The hydraulic system is then used to lift the frame of the forklift to a suitable level above the ground to allow its transportation with the carrier vehicle. The forklift projects from the trailing end of the carrier. The weight of the forklift is borne by the forks, carriage and mast.
An example of this type of structure is illustrated in U.S. Pat. No. 3,799,379 and it includes a cable 158 mounted on a shaft 154 on the trailing end of the carrier. The cable has an eye 160 at one end and it slides over a hook 162 mounted on the frame of the forklift. The cable is then tightened and maintained in tension by a ratchet 156. Thereby the forklift is prevented from separating from the carrier due to bumps and bounces during transportation from one site to another. One problem which this patent does not solve is the bending, flexing and constant tension of the forks mounted on the mast and carriage of the forklift.
A similar structure is illustrated in U.S. Pat. No. 4,396,341 which includes vertically displaced cross bars on the end of a carrier for the forks. The forklift is lifted in the same way as described in the paragraph above. However, there is a significant difference in that the carrier structure of this patent includes a pair of wheel pockets 78 transversely located on each side of the fork supporting cross bars to house the forward wheels of the forklift. The wheel pockets 78 restrict the movement of forward wheels 24 of the forklift in forward, upward and downward directions. To a certain extent this relieves the problem of strain on the carriage, mast and forks. The patent provides for links 106 extending between the carrier frame and the forklift frame to hold the forklift in position to prevent accidental release due to bounces and the like.
Two commonly owned patents, U.S. Pat. Nos. 4,921,075 and 5,174,415 illustrate other means for mounting forklifts on the trailing end of a carrier vehicle. Neither discloses the problem of relieving strain on the forks, carriage, and mast.
The problems which exist in the industry are strain on the forks, carriage and mast as described above and providing a secure lock to hold the forklift on the carrier vehicle. This invention solves these problems.